Method of making hollow flexible boots



- De 3,1946, M. E. GOLDEN 2,411,874

METHOD OF M OOTS Patented Dec. 3, 1946 UNITED STAT-E METHOD OF MAKINGHOLLOW FLEXIBLE I BOOTS Milton E. Golden, Chicago, 111.

Application November 27, 1943, Serial No. 511,930

, 2 Claims. (01. 64-32) (Granted under the act of March 3, 1883, as

The invention described herein may be manufactured and used by or forthe Government for governmental purposes, without the payment to me ofany royalty thereon.

This invention relatesto flexible boots of the kind employed to encase amechanical structure which is subject to elongation or bending inoperation. Boots of this class are employed-to keep lubrication in,or'dirt out, or both, yet they must allow freedom of movement of themechanism within.

An object of the invention is to provide a boot of this descriptionwhich may be made of readily available material with minimum waste ofstock used and time consumed in the making.

Another object of the invention is to develop a novel method ofproducing the device which is herein shown and described as anembodiment of my invention.

Other objects and advantages Will be evident as the invention is furtherdescribed and reference is made to the drawing, wherein:

Fig. 1 shows a washer cut from sheet material, this being a first stepin making one of the units of my device.

Fig. 2 shows the washer of Fig. l-after it has been cut through on aradial line, this being the second step in the production of a unit ofmy device.

Fig. 3 shows a series of the cut washers of Fig. 2 after the ends, whichwere provided by the cuts, were drawn apart so as to. pull each washerinto a somewhat exaggerated lock washer shape.

Fig. 4 shows a series of the lock washer shapes of Fig. 3 with the endof one washer permanently joined to the beginning of the next so as toprovide, of the several separate washers, a continuous helix.

Fig. 5 shows two of the helices of Fig. 4 laid together with theconvolutions of one alongside the convolutions of the other preparatoryto joining their edges.

Fig. 6 shows how the inner edges of the two helices of Fig. 5 may bepermanently joined, while the outer edges lie contiguous but are notfastened together.

Fig. '7 shows how the outer edges of contiguous convolutions of Fig. 6are drawn apart preparatory to securing them together, the one of onepair to the other of the next pair.

Fig. 8 shows the drawn-together outer convolutions after they have beenpermanently joined.

In the drawing, a series of washers l9, Fig. 1, are preferably cut froma sheet of flexible fabric, or thin metal, as the case may require- Eachamended April 30,

, stage the outer washeris then slit to compose a split washer [2, Fig.2, the slit extending from the inner diameter M of the washer to theouter diameter l6, thereby providing the piece with two abutting ends 3and 20. I

The ends l8 and 2B of the split washers l2, Fig. 2, are then pulledapart as shown in Fig. 3, so as to compose of each piece an exaggeratedlock washer shape 22, each piece thus composing one turn of a helix.Three pieces thus treated are shown in Fig. 3, being numbered 22, 22aand 221), the ends of the first piece being referred to as 18 and 20,the ends of the second as l8a and 20a, and the ends of the third as I81)and 20b.

The adjacent ends of the several helical turns 22, 22a and 221) are nextfastened together in some suitable manner being preferably sewn if thematerial is flexible fabric, or being soldered or welded if it is metal,the end 29 being joined to lBa, 29a to I81), etc. When the several endshave been thus joined together, a continuous helix 24, Fig. 4, will havebeen formed, having an inside helical edge I la and an outside helicaledge Ilia, the individual convolutions being designated 24a, 2419,2 50and 24d.

When two helices M, as shown in Fig. 4 have been provided, theymay beput together as shown in Fig. 5, the second helix, however, beingassigned the numeral 25 to facilitate description, and its individualconvolutions being for the same reason given the numerals 25a, 25b, 25cand 25d. The inner edge of the helix 25 will be referred to as Mb andthe outer edge ltb.

After the two helices 24 and 25 have been assembled as shown in Fig 5,the inner edges of the two, that is, the edges Ma and lb may be laidtogether and sewn or otherwise joined as shown in Fig. 6. The sewingtogether of these two edges will consist of one continuous seamthroughout the length of the helices. At this edges i511 and Nib stilllie alongside but are not fastened together.

After the two helices 24 and 25 are thus joined at the inner edges Idaand Nb, the outer edges Ilia and Hib are pulled apart as shown in Fig.'7, and paired anew, that is, instead of 25a and 25a lying alongside,25a will be paired with 24b, 25b will be paired with 240, 25c with 24d,etc.

When the outer edges are now sewn together in one continuous seam, thedevice will have assumed the configuration of Fig. 8, that is, it willhave the form of a hollow V screw thread. Here the inner edge of 24a. ispaired with the inner edge of 25a, then the outer edge of 25a with theouter edge of 2%, etc. Finally appropriate end pieces 26 and 27 arejoined to the ends of the screw, their shape depending on the shape ofthe part which is to be housed.

In addition to the concentric helically shaped exible boot made ofcircular discs of uniform diameters as hereinbefore described, variousconacter indicated.

It is noted that since the boot is built in the form of a helix it isobviously stronger than one made of circular discs in the conventionalmanner, that is, sewn together along their inner and outercircumferences. Distortion and stresses are transmitted in a helicaldirection to all sections of the assembly simultaneously and uniformly,thus making the workin life of the boot, made according to subJectinvention, longer.

It is further noted that a boot made to subject invention of 1. Themethod of making a hollow flexible boot from relatively thin flexiblesheet material, which consists of cutting out a series of washers,radially slitting said continuous seam, the first convolution of thesec-- ond helix to the second convolution of the first helix.

2. Steps in the method of making a hollow flexible boot MILTON E.GOLDEN.

